IPACS modeling and dynamical analysis of a flexible spacecraft

The dynamical equations of a flexible spacecraft with VSCMGs (variable speed control moment gyroscopes) are established via the Lagrange equations in terms of quasi-coordinates and the momentum theorem. The equations are suitable for both attitude control law design and VSCMGs steering law design. Singularity may occur when VSCMGs are used for attitude control and energy storage, which is avoided effectively via momentum management and configuration design of VSCMGs. The dynamical coupling between the IPACS (integrated power/attitude control system) and vibration of flexible spacecraft with VSCMGs is analyzed. The numerical simulation for a large-scale flexible spacecraft with IPACS is carried out. The simulating results show, when either the torque axes of VSCMGs are near singularity (or enter singularity) or the power is conversed, that the motion of VSCMGs markedly influences flexible appendages.